Noise Analysis of Dry Transformer in the Laboratory Conditions

The article focuses on the method of assessing the instability of noise and the size of a dry transformer using acoustic emission in laboratory conditions. The experimental measurement was conducted to obtain reference values for the acoustic emission size and its instability of acoustic noise for a well-functioning dry transformer rated at 22000/6000 V in the laboratory. These reference values were then compared with the actual values of the transformer during its operational phase. The measurement utilized a noise measuring device with a three-octave spectral filter, covering the frequency range from 100 Hz to 10 kHz, over a period of 20 seconds. Specifically, a CESVA SC250 measuring device was employed for noise measurement through acoustic emission analysis. It simultaneously measures all parameters, considering both frequency and time parameters across various time bases. These measurements serve as reference values for analyzing the condition of dry transformers of the same type and performance. After operation or repair, transformers can be sent for inspection to test laboratories for comparison and evaluation.